Reliability modelling for the GIL subject to competing failure modes

摘要

Due to necessity of enforcing the electrical transmission network, a long distance gas insulated transmission line (GIL) has been developed as a new alternative underground technology, and has shown an ever-increasing usage worldwide. The main failure modes of the GIL are performance degradation due to air leakage, and random shocks caused by partial discharge. The failure of the GIL subject to both soft failure and hard failure is the result of their competition. Considering that the degradation occurs only after a certain delay, i.e. there is a random degradation initiation time before the air in the GIL begins to leak, this paper presents a new reliability model for the GIL subject to competing failure modes. Its reliability is assessed through analytical derivation and numerical calculation methods. And a numerical study is conducted to illustrate the implementation of the proposed model.